The value of crude oils is often dependent on the corrosivity of the oil, and corrosivity is mainly a function of the total acid number of the oil. TAN, in turn, is heavily dependent, although not completely so, on the naphthenic acid concentration of the oil. Consequently, crudes having a relatively high TAN, e.g., .gtoreq.2 have a significantly lower market value, on a per barrel basis, than crudes having a relatively lower TAN. For example, high TAN crudes are often blended off with lower TAN crudes rather than being processed separately through refineries, thereby avoiding excessive corrosion in refinery equipment. Processing of high TAN crudes can also necessitate the use of expensive alloys in primary equipment, e.g., pipestills, thereby minimizing corrosivity effects of the crudes. Both methods for handling high TAN crudes are expensive and can lead to excessive storage facilities or upsets in the refinery. Consequently, there remains a need for handling high TAN crudes that is not disruptive of refinery operations and avoids excessive costs.